Wikipedia
The diamond hitch is a lashing technique used mainly in the field of equine packing, to secure a set of objects, for instance a pair of pack-bags, pack-boxes or other gear onto a base, for instance a pack saddle frame, in which case it requires the use of a lash cinch. In the general sense it requires the base to be equipped with at least two points of anchorage, and a rope which is used to lash the object down onto the base. There are two types of Diamond Hitches, a single, shown here, and a double diamond hitch which is not shown.
Usage examples of "diamond hitch".
Working swiftly, he unraveled the diamond hitch, pulled the hemp rope from the pack, and unbuckled the wooden box panniers.
I tied my end of the sash cord around my ankle with a firm, double-knotted diamond hitch.